[fix] fix actuator control with actuator-joint mapping

[Dingry]

What this does

The exisiting joint controllers (JointPositionController, JointVelocityController, and JointTorqueController) would break under two conditions:

• When the sequence of actuators didn't match the sequence of joints
• When the number of joints didn't equal the number of actuators, which can occur due to joint constraints (like equality constraints or tendon mechanisms)

The PR fixes this with actuator-joint indexing and mapping in the control function.